Latrine closure mechanism

ABSTRACT

A TRAP DOOR AUTOMATICALLY COVERS APERTURE IN LATRINE WHEN LATRINE IS NOT IN USE AND SWINGS DOWN AND AWAY FROM APERTURE IN RESPONSE TO LIGHT DOWNWARD PRESSURE ON SEAT OR TREADLE WHEN LATRINE IS IN USE. THE MECHANISM IS MADE OF SIMPLE BUTT HINGES OR THEIR EQUIVALENT AND SMALL PIECES OF METAL OR WOOK, AND INCLUDES A SIMPLE   COUNTER WEIGHT TO HOLD THE TRAP DOOR NORMALLY IN APERTURE COVERING POSITION. THE IDENTICAL MECHANISM MAY BE USED WITH EITHER SEAT OR SQUAT-TYPE TREADLE.

Jan.- 5, 1971 G. IMMEGA -LTRINE CLOSURE MECHANISM Filed Dec. 21, 1967 2 Sheets-Sheet 1 FIG. 2

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GUY IMMEGA FIG. 3

Jan. 5, 1971 G. IMMEGA LATRINE CLOSURE MECHANISM 2 Sheets-Sheet 2 Filel Dec. 21. 1967 7 FIG@ INYENTR GUY IMA/)EGA v /m'oRNw 3,551,917 LATRINE CLOSURE MECHANISM Guy Immega, 11511 Meyer, University City, Mo. 63130 Filed Dec. 21, 1967, Ser. No. 692,594 Int. Cl. A47k 11/02 U.S. Cl. 4-144 6 Claims ABSTRACT F THE DISCLOSURE A trap door automatically covers aperture in latrine when latrine is not in use'and swings down and away from aperture in response to light downward pressure on seat or treadle when latrine is in use. The mechanism is made of simple butt hinges or their equivalent and small pieces of metal or wood, and includes a simple counter weight to hold the trap door normally in aperture covering position. The identical mechanism may be used with either seat or squat-type treadle.

BACKGROUND OF THE INVENTION This invention relates to a latrine for use in areas where modern plumbing is not available. In many parts of the word there are practically no water closets or even screened privies, and consequently most of the people still use open outdoor latrines. No simple effective way has yet been devised to keep these latrines covered. As a result, the maintenance of even minimum standards of sanitary conditions is virtually impossible.

One of the objects of this invention is to provide a device which Will automatically cover and uncover latrine apertures.

Another object of this invention is to provide such a device which is durable, economical, feasible to make and install under primitive conditions, and simple in operation.

Other objects will occur to those skilled in the art in the light of the following description and accompanying drawings.

SUMMARY OF THE INVENTION In accordance With this invention, generally stated, an automatic latrine cover mechanism is provided in the form of a trap door attached to a hinge mechanism, the hinge mechanism being suspended from a base in the form of a latrine floor or seat support board having an aper ture in it, the hinge mechanism having a counterweight, and being attached to a part of a body support in the form of a seat or treadle of the latrine. Another part of the seat or treadle is pivoted on the latrines floor or seat support board. The hinge mechanism normally holds the seat or treadle in partly elevated position, and the trap door in base aperture closing position. The imposition of weight on the seat or treadle causes the seat or treadle to descend, and moves the hinge mechanism against the bias of the counterweight, and the trap door to base aperture clearing position.

The hinge mechanism is so arranged that the trap door is moved back as it moves down, and not only requires no springs or other sophisticated parts, but can be fashioned from strips of leather or other pliable material and small pieces of wood.

United States Patent O 'ice In the preferred embodiment, the hinge mechanism has a center hinge, a cross piece hinged near its center to the center hinge, a counterweight hingedly connected to the cross piece on one side of the center hinge axis, and a trap door bracket and a body support stanchion mounted on the cross piece on the other side of the center hinge axis. In the device illustrated, the stanchion is hinged along an axis parallel to and spaced from the center hinge axis, to a surface of the trap door bracket, which is fixedly mounted on a surface of the cross piece. A seat or treadle is hinged to the upper end of the stanchion.

The center hinge is mounted on the underside of the latrine floor or seat support board.

BRIEF DESCRIPTION OF THE DRAWINGS In the drawings, FIG. l is a fragmentary top plan view of one illustrative seat type embodiment of automatic latrine cover mechanism of this invention in base aperture closed position;

FIG. 2 is a top -plan view of a trap door of the device shown in FIG. 1;

FIG. 3 is a fragmentary top plan view of one illustrative example of treadle type embodiment of automatic latrine cover of this invention in closed position;

FIG. 4 is a top plan view of a trap door of the device shown in FIG. 3;

FIG. 5 is a sectional view taken along the line 5 5 of FIG. 1, showing a hinge mechanism with seat in raised position above the seat support board and trap door in closed position;

FIG. 6 is a sectional view corresponding to the view shown in FIG. 5 of the hinge mechanism shown in FIG. 5 with the seat down, and in dotted lines, tilted back, and the trap door in open position;

FIG. 7 is a fragmentary sectional view of the treadle of FIG. 3 is raised position above the latrine floor with the trap door in closed position; and

FIG. 8 is a View in perspective of the counterweight and a portion of the hinge mechanism.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring now to the drawing and particularly to FIGS. 1, 2, 5, 6 and 8, for one illustrative embodiment of latrine closure mechanism of this invention, reference numeral 1 indicates a seat of the type commonly used on water closets. The seat 1 rests on a pivot bar 2, shown in dotted lines in FIG. l, on a seat support or base 5, The seat support board 5 is the top of an open-bottomed box-like structure, not here shown, above a latrine pit.

At its rear edge, the seat 1 is connected by means of a seat hinge 10 to a stanchion 15. The seat hinge 10, in the embodiment shown, is a simple butt hinge with a leaf 11 fastened to the underside of the seat by means of screws, a leaf 12 fastened to one side face of the stanchion 15, and the usual knuckle and pintle arrangement, preferably with four knuckles, of butt hinges. In this illustrative embodiment, the stanchion 15 is made of metal and the hinge leaf 12 is welded, brazed or otherwise secured to the face of the stanchion.

The stanchion 15 extends through a hole 6 in the seat support board 5. Another aperture 7 in the seat support board is of the same shape but slightly larger than the central aperture in the seat 1.

The stanchion has a spur 16 projecting laterally from the side of the stanchion opposite the side on which the seat is mounted. The spur 16 is of a width and length to close the hole 6 when the seat is in the position shown in FIG. 5. The stanchion 15 is as Wide as the hinge 10, and the hole 6 is only wide enough to permit the stanchion to move freely up and down.

A stanchion hinge 20 has one leaf 21 welded, brazed or otherwise secured to a surface of the stanchion 15 below the spur 16 and on the opposite side of the stanchion from the face to which the said hinge 10 is secured. Another leaf 22 of the hinge 20 is secured to a surface of a trap door bracket 30.

The trap door bracket is a dog leg bracket with parallel hinge surfaces 31 and 32, a dog leg 33, and a trap door leg 34. In the embodiment shown, the hinge surfaces 31 and 32 are perpendicular to the dog leg 33, and the trap door leg 34 makes an acute angle with the dog leg 33, to make the trap door leg 34 parallel with the underside of the seat support board 5 in the position of the d seat shown in FIG. 5.

A trap door 70, of a shape and size such as to fit well within the outline of the seat board and connes of the seat support box structure, to permit its swinging down, as shown particularly in FIGS. l and 2, is fastened, by means of screws 71 to trap door leg 34 of the bracket 30. The trap door leg 34 is spaced from the underside of the seat support board 5 a distance to permit the trap door 70 to fit flush against the underside of the seat support board, thus closing tightly the aperture 7 in the seat support board, When the trap door is in the position shown in FIGS. l and 5. In the embodiment shown, the acute angle which the trap door leg 34 makes with the dog leg 33 causes the trap door leg 34 and the trap door 70 to angle away from the aperture 7 in the position of the seat shown in FIG. 6.

The trap door bracket 30 is secured, on its face 31, to a center hinge 40, one leaf 41 of which is Welded, brazed or otherwise secured to the surface 31 of the trap door bracket. Another leaf 42 is secured to a leg 46 of an angleiron hanger 45. Another leg 47 of the hanger is mounted to and on the underside of the seat support board 5 by means of screws 48.

A crosspiece 50 is secured to the face of the leaf 41 opposite the face to which the trap door bracket 30 is secured. The crosspiece 50 projects a substantial distance past the knuckles and pintle, i.e. the axis, of the center hinge 40. The crosspiece 50 constitutes a counterbalance lever, and the distance it projects beyond the hinge axis of center hinge 40 determines the relation of Weight of o the trap door 70, seat 1 and a counterbalance weight or counterweight 80.

The counterbalance weight 80 has a spline 81, secured along its top edge to a leaf 61 of a counterweight hinge 60, another leaf 62 of which is secured to the projecting end of the crosspiece 50. In this embodiment, the hinge leaf 62 is shown as secured to the underside of the crosspiece 50, the side opposite the side to which the hinge leaf 41 is secured.

The counterweight 80 is of such a size as to hold the trap door in closed position with the least pressure consonant with effective closing. In practice, the trap door and weight can be so balanced that the additional weight of the seat when it is raised as shown in dotted lines in FIG. 6, Will unbalance the counter weight and cause the trap door to assume the position shown in FIG. 6. The pivot bar 2 is mounted on only one of the seat or seat support board, and preferably rests in a shallow cut out portion in the other, so that the seat can be swung up as shown in FIG. 6.

When one sits on the seat, the seat needs to move only a short distance, for example 4.5 cm., to depress the trap door. Again in this embodiment, in which a seat support box is likely to be provided to raise the seat to a comfortable position, the box and the pit below it are 4 so dimensioned as to permit the trap door to swing down freely and the counterweight to be clear in its travel.

Referring now to FIGS. 3, 4 and 7 for another embodiment of latrine cover mechanism of this invention, reference numeral 101 indicates a treadle which is hinged at its front edges by simple hinges 102 to a latrine floor in base 105. The treadle 101 is yoke shaped with a central opening extending from and through its front edge. The latrine oor 105 has in it a key-hole shaped aperture 107, which extends forwardly of the front edges of the treadle 101. A trap door beneath the floor 105 is of a shape and size to close the aperture 107 but to swing down freely into a pit beneath the oor 105. The oor 105 has a hole 106 in it corresponding exactly to the hole 6 in the seat support board of the first embodiment. Actually, the hole 106 does not need a chamfer like that of the hole 6, to accommodate the seat, because the treadle 101 is mounted against translation at its front edge by means of the hinges 102, which precludes its being raised in the manner of the seat.

All of the rest of the mechanism in this embodiment is identical with that of the embodiment shown in FIGS. 5, 6 and 8 and described in connection with the rst embodiment.

rI'he treadle type is particularly for use in most parts of Africa and Asia, in which the people customarily squat in defecating and urinating. When one stands on the treadle as indicated by the feet position lines in FIG. 3, his Weight moves the trap door down in the same way as the weight of one sitting on the seat moves the trap door down as shown in FIG. 6.

The hinge mechanism of both embodiments is simple to manufacture. If the stanchion, trap door bracket, crosspiece, hanger and counterweight, and all of the butt hinges are preassembled, it is only necessary to mount the trap door and body support on the hinge mechanism and to mount the hinge mechanism to the under side of the base.

While the prefabrication, from metal, of the hinge mechanism has many advantages, including the advantage that the dimensions and the relative position of the parts are predetermined by the dimnesions and configuration of the hinge mechanism, so that if the trap door is made of quarter-inch marine plywood, for example, it will always t properly if the hinge mechanism is made to accommodate that particular material, and the metal parts are strong and durable, the hinge mechanism is adapted to be made of native materials under primitive conditions. For example, the stanchion, trap door bracket, crosspiece and counterweight, and a piece corresponding to the hanger 45, can all be fashioned of wood, and the hinges can be made of leather or other pliable material.

On the other hand, more sophisticated materials, such as plastic, can also be used.

It; will be noted that because the center hinge axis is offset from the hole 6 or 106, as the case may be, in a direction away from the aperture '7 or 107, the stanchion and trap door are both, in effect, translated away from the base aperture when the stanchion is depressed. This has several advantages. First, it moves the trap door and stanchion farther out of the path of feces; second, it permits the front edge of the body support to remain in a fixed position laterally relative to the base, and third, particularly in the seat version, it provides a closure means for the hole through 'which the stanchion projects when the body support is in its stanchion depressing position.

The possibility that the trap door will become soiled in use is further lessened by the angling away of the trap door from the aperture 7 or 107 when the stanchion is depressed.

Merely by way of example, and not by way of limitation, a satisfactory hinge mechanism can be made of metal (preferably bronze, stainless steel, or other corrosion-resistant metal, though iron or steel plain or galvanized or Bonderized, may be used, if necessary), with the following dimensions, all in centimeters:

Stanchion height 8.3 Spur projection 1.1 Trap door bracket length 7.8 Height of dog leg 2.2

Thickness of bracket between surfaces 31 and 32 1 Angle between dog leg and trap door leg (degrees) 79 Hanger mounting leg length 4.0 Hanger depending leg length 3.3 Crosspiece length 5.5 Distance along crosspiece from the center hinge axis to the end at which the counterweight hinge 60 is secured 3.3 Width of all metal parts except the hinges 6.0 Thickness of all metal parts except the hinges 0.5 Width of all hinge leaves 2.5 Length of all hinge leaves 6.0 Seat trap door width 27 Seat trap door length 35.5 Seat trap door thickness l Treadle trap door width 22 Treadle trap door length 46.5 Treadle trap door thickness l Thickness of base 2 Overall width of treadle 64.5 Length of treadle fore and aft 50 Height of counterweight spine 7.5 Diameter of counterweight 4.0

As has been indicated, these dimensions are merely illustrative.

The absolute value of the weight of the counterweight will depend upon the weight and length of the trap door and seat or treadle and will have to be determined for the particular style of trap door and seat or treadle and material used for their construction.

It can be seen from the illustrative dimensions given that the mechanism can be quite compact.

Numerous variations within the scope of the appended claims in the construction of the latrine closure mechanism of this invention will occur to those skilled in the art in the light of the foregoing disclosure.

Having thus described the invention, what is claimed `and desired to be secured by Letters Patent is:

1. A latrine closure mechanism comprising a base having an aperture therein; a relatively wide-leaved center hinge mounted on said base; a trap door supported by said center hinge and mounted to swing between base aperture closing and base aperture clearing positions; a body support mounted on said base; a wide body support stanchion hinge'ways connected to said body support and hingeways connected to said center hinge for vertical movement to a position at which it projects above said base; a crosspiece mounted on said center hinge, and counterbalance means connected to said crosspiece and counterbalancing the weight of the trap door and a portion of the weight of the body support and biasing said trap door toward base aperture closing position and said body support to a position at which a part of said body support is raised above said base.

2. The latrine closure mechanism of claim 1 wherein the body support is a yoke-shaped treadle with a substantial foot-receiving area on either side of a central opening, hingeways mounted at its front to the base.

3. The latrine closure mechanism of claim 1 wherein the stanchion projects through a hole in the base spaced from the said base aperture and a spur is provided on the stanchion to bridge the said hole when the trap door is in base aperture closing position.

4. The latrine closure mechanism of claim 3 wherein the center hinge axis is otset from the hole in the base in a direction away from the base aperture, the stanchion moves in the direction of the center hinge axis when the body support and stanchion move downwardly, and the body support covers the open portion of the hole when the body support is in its stanchion-depressing position.

5. The latrine closure mechanism of claim 1 wherein a dogleg trap door bracket is secured to the center hinge, the trap door is mounted on a leg of the trap door bracket, and the stanchion is hingedly connected to another leg of the trap door bracket between the trap door and the center hinge axis.

6. A latrine closure mechanism comprising a base having an aperture therein; a relatively wide-leaved center hinge mounted on said base; a trap door supported by said center hinge and mounted to swing between base aperture closing and base aperture clearing positions; a seat, the front of said seat being unsecured to, but normally resting upon said base; a relatively wide seat support stanchion hingedly connected to the rear of said seat and hingedly connected to said center hinge for vertical movement to a position at which said stanchion projects above said base; a cross piece mounted on said center hinge, and counterbalance means connected to said cross piece and counterbalancing the weight of the trap door and a portion of the weight of the seat and biasing said trap door toward base aperture closing position and said seat to a position at which the rear of said seat is raised above said base when the front of the seat is resting upon the base, said seat being of such weight relative to the counterbalance means as to overbalance said counterbalance means when the front of the seat is raised to substantially vertical position, to cause the trap door to move to base aperture clearing position.

References Cited UNITED STATES PATENTS 56,881 8/1866 Beach 4-143 58,400 10/1866 Forney 4-136 223,131 12/1879 Gorman 4-144 898,225 9/ 1908 Kelley 4-144 1,664,426 4/1928 Lang 4-144 2,680,249 6/1954 Yamada et al. 4-128 3,366,976 2/1968 Swanson 4-144 FOREIGN PATENTS 165,017 9/1955 Australia 4-144 232,856 2/1961 Australia 4-144 1,940 2/1885 Great Britain 4-144 69,965 1/1892 Germany 4-144 LAVERNE D. GEIGER, Primary Examiner D. R. MASSENBERG, Assistant Examiner UNITED STATES PATENT OFFICE CERTIFICATE OF CGRRECTION Patent No. 3 551 917 Dated January 5 1971 Gu Imme a Inventor(s) y g It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as show-n below:

In the heading to the printed specification, line 3, "11511 Meyer, University" should read 1154 Meyer: University Signed and sealed this 20th day of July 1971 (SEAL) Attest:

EDWARD M.FLETCHER,JR. WILLIAM E. SCHUYLER, J Attesting Officer Commissioner of Patent l FORM PID-1050 (1D-69) 

